-# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 2020-2021 all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
# for systems lacking Linux::Inotify2 or IO::KQueue, just emulates
# enough of Linux::Inotify2
package PublicInbox::FakeInotify;
use strict;
+use v5.10.1;
+use parent qw(Exporter);
use Time::HiRes qw(stat);
-my $IN_CLOSE = 0x08 | 0x10; # match Linux inotify
+use PublicInbox::DS qw(add_timer);
+sub IN_MODIFY () { 0x02 } # match Linux inotify
+# my $IN_MOVED_FROM 0x00000040 /* File was moved from X. */
+# my $IN_MOVED_TO = 0x80;
+# my $IN_CREATE = 0x100;
+sub MOVED_TO_OR_CREATE () { 0x80 | 0x100 }
+sub IN_DELETE () { 0x200 }
+sub IN_DELETE_SELF () { 0x400 }
+sub IN_MOVE_SELF () { 0x800 }
+
+our @EXPORT_OK = qw(fill_dirlist on_dir_change);
my $poll_intvl = 2; # same as Filesys::Notify::Simple
-my $for_cancel = bless \(my $x), 'PublicInbox::FakeInotify::Watch';
-sub poll_once {
- my ($self) = @_;
- sub {
- eval { $self->poll };
- warn "E: FakeInotify->poll: $@\n" if $@;
- PublicInbox::DS::add_timer($poll_intvl, poll_once($self));
- };
-}
+sub new { bless { watch => {}, dirlist => {} }, __PACKAGE__ }
-sub new {
- my $self = bless { watch => {} }, __PACKAGE__;
- PublicInbox::DS::add_timer($poll_intvl, poll_once($self));
- $self;
+sub fill_dirlist ($$$) {
+ my ($self, $path, $dh) = @_;
+ my $dirlist = $self->{dirlist}->{$path} = {};
+ while (defined(my $n = readdir($dh))) {
+ $dirlist->{$n} = undef if $n !~ /\A\.\.?\z/;
+ }
}
# behaves like Linux::Inotify2->watch
sub watch {
- my ($self, $path, $mask, $cb) = @_;
+ my ($self, $path, $mask) = @_;
my @st = stat($path) or return;
- $self->{watch}->{"$path\0$mask"} = [ @st, $cb ];
- $for_cancel;
+ my $k = "$path\0$mask";
+ $self->{watch}->{$k} = $st[10]; # 10 - ctime
+ if ($mask & IN_DELETE) {
+ opendir(my $dh, $path) or return;
+ fill_dirlist($self, $path, $dh);
+ }
+ bless [ $self->{watch}, $k ], 'PublicInbox::FakeInotify::Watch';
+}
+
+# also used by KQNotify since it kevent requires readdir on st_nlink
+# count changes.
+sub on_dir_change ($$$$$) {
+ my ($events, $dh, $path, $old_ctime, $dirlist) = @_;
+ my $oldlist = $dirlist->{$path};
+ my $newlist = $oldlist ? {} : undef;
+ while (defined(my $base = readdir($dh))) {
+ next if $base =~ /\A\.\.?\z/;
+ my $full = "$path/$base";
+ my @st = stat($full);
+ if (@st && $st[10] > $old_ctime) {
+ push @$events,
+ bless(\$full, 'PublicInbox::FakeInotify::Event')
+ }
+ if (!@st) {
+ # ignore ENOENT due to race
+ warn "unhandled stat($full) error: $!\n" if !$!{ENOENT};
+ } elsif ($newlist) {
+ $newlist->{$base} = undef;
+ }
+ }
+ return if !$newlist;
+ delete @$oldlist{keys %$newlist};
+ $dirlist->{$path} = $newlist;
+ push(@$events, map {
+ bless \"$path/$_", 'PublicInbox::FakeInotify::GoneEvent'
+ } keys %$oldlist);
}
-# behaves like non-blocking Linux::Inotify2->poll
-sub poll {
+# behaves like non-blocking Linux::Inotify2->read
+sub read {
my ($self) = @_;
- my $watch = $self->{watch} or return;
+ my $watch = $self->{watch} or return ();
+ my $events = [];
+ my @watch_gone;
for my $x (keys %$watch) {
my ($path, $mask) = split(/\0/, $x, 2);
- my @now = stat($path) or next;
- my $prv = $watch->{$x};
- my $cb = $prv->[-1];
- # 10: ctime, 7: size
- if ($prv->[10] != $now[10]) {
- if (($mask & $IN_CLOSE) == $IN_CLOSE) {
- eval { $cb->() };
+ my @now = stat($path);
+ if (!@now && $!{ENOENT} && ($mask & IN_DELETE_SELF)) {
+ push @$events, bless(\$path,
+ 'PublicInbox::FakeInotify::SelfGoneEvent');
+ push @watch_gone, $x;
+ delete $self->{dirlist}->{$path};
+ }
+ next if !@now;
+ my $old_ctime = $watch->{$x};
+ $watch->{$x} = $now[10];
+ next if $old_ctime == $now[10];
+ if ($mask & IN_MODIFY) {
+ push @$events,
+ bless(\$path, 'PublicInbox::FakeInotify::Event')
+ } elsif ($mask & (MOVED_TO_OR_CREATE | IN_DELETE)) {
+ if (opendir(my $dh, $path)) {
+ on_dir_change($events, $dh, $path, $old_ctime,
+ $self->{dirlist});
+ } elsif ($!{ENOENT}) {
+ push @watch_gone, $x;
+ delete $self->{dirlist}->{$path};
+ } else {
+ warn "W: opendir $path: $!\n";
}
}
- @$prv = (@now, $cb);
}
+ delete @$watch{@watch_gone};
+ @$events;
+}
+
+sub poll_once {
+ my ($obj) = @_;
+ $obj->event_step; # PublicInbox::InboxIdle::event_step
+ add_timer($poll_intvl, \&poll_once, $obj);
}
package PublicInbox::FakeInotify::Watch;
-sub cancel {} # noop
+use strict;
+
+sub cancel {
+ my ($self) = @_;
+ delete $self->[0]->{$self->[1]};
+}
+
+sub name {
+ my ($self) = @_;
+ (split(/\0/, $self->[1], 2))[0];
+}
+
+package PublicInbox::FakeInotify::Event;
+use strict;
+
+sub fullname { ${$_[0]} }
+
+sub IN_DELETE { 0 }
+sub IN_MOVED_FROM { 0 }
+sub IN_DELETE_SELF { 0 }
+
+package PublicInbox::FakeInotify::GoneEvent;
+use strict;
+our @ISA = qw(PublicInbox::FakeInotify::Event);
+
+sub IN_DELETE { 1 }
+sub IN_MOVED_FROM { 0 }
+
+package PublicInbox::FakeInotify::SelfGoneEvent;
+use strict;
+our @ISA = qw(PublicInbox::FakeInotify::GoneEvent);
+
+sub IN_DELETE_SELF { 1 }
1;